Yes, I know they are single ended, but the amps were apparently ordered that way for the previous owner. And considering I already had 30' of balanced cables running to the front of the room (let alone the only cables long enough to reach to the front of the room), I used the balanced inputs on the amps.I have a Stratos, they are single ended. While there is an XLR in, pin 3 is left completely disconnected. IMO, XLR in should be an extra cost option with an input trafo used, but since that's not the case RCA in is better.
It was shortly after that I was having noise issues and I purchased the new single ended cables which resolved the issue.